xref: /freebsd/lib/libfetch/common.c (revision 4db3872aabc33088cf180599c5eaa23b6f58e6d1)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1998-2016 Dag-Erling Smørgrav
5  * Copyright (c) 2013 Michael Gmelin <freebsd@grem.de>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer
13  *    in this position and unchanged.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/param.h>
33 #include <sys/socket.h>
34 #include <sys/time.h>
35 #include <sys/uio.h>
36 
37 #include <netinet/in.h>
38 
39 #include <ctype.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <inttypes.h>
43 #include <netdb.h>
44 #include <paths.h>
45 #include <poll.h>
46 #include <pwd.h>
47 #include <stdarg.h>
48 #include <stdlib.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 #ifdef WITH_SSL
54 #include <openssl/x509v3.h>
55 #endif
56 
57 #include "fetch.h"
58 #include "common.h"
59 
60 
61 /*** Local data **************************************************************/
62 
63 /*
64  * Error messages for resolver errors
65  */
66 static struct fetcherr netdb_errlist[] = {
67 #ifdef EAI_ADDRFAMILY
68 	{ EAI_ADDRFAMILY, FETCH_RESOLV, "Address family for host not supported" },
69 #endif
70 #ifdef EAI_NODATA
71 	{ EAI_NODATA,	FETCH_RESOLV,	"No address for host" },
72 #endif
73 	{ EAI_AGAIN,	FETCH_TEMP,	"Transient resolver failure" },
74 	{ EAI_FAIL,	FETCH_RESOLV,	"Non-recoverable resolver failure" },
75 	{ EAI_NONAME,	FETCH_RESOLV,	"Host does not resolve" },
76 	{ -1,		FETCH_UNKNOWN,	"Unknown resolver error" }
77 };
78 
79 /*
80  * SOCKS5 error enumerations
81  */
82 enum SOCKS5_ERR {
83 /* Protocol errors */
84 	SOCKS5_ERR_SELECTION,
85 	SOCKS5_ERR_READ_METHOD,
86 	SOCKS5_ERR_VER5_ONLY,
87 	SOCKS5_ERR_NOMETHODS,
88 	SOCKS5_ERR_NOTIMPLEMENTED,
89 	SOCKS5_ERR_HOSTNAME_SIZE,
90 	SOCKS5_ERR_REQUEST,
91 	SOCKS5_ERR_REPLY,
92 	SOCKS5_ERR_NON_VER5_RESP,
93 	SOCKS5_ERR_GENERAL,
94 	SOCKS5_ERR_NOT_ALLOWED,
95 	SOCKS5_ERR_NET_UNREACHABLE,
96 	SOCKS5_ERR_HOST_UNREACHABLE,
97 	SOCKS5_ERR_CONN_REFUSED,
98 	SOCKS5_ERR_TTL_EXPIRED,
99 	SOCKS5_ERR_COM_UNSUPPORTED,
100 	SOCKS5_ERR_ADDR_UNSUPPORTED,
101 	SOCKS5_ERR_UNSPECIFIED,
102 /* Configuration errors */
103 	SOCKS5_ERR_BAD_HOST,
104 	SOCKS5_ERR_BAD_PROXY_FORMAT,
105 	SOCKS5_ERR_BAD_PORT
106 };
107 
108 /*
109  * Error messages for SOCKS5 errors
110  */
111 static struct fetcherr socks5_errlist[] = {
112 /* SOCKS5 protocol errors */
113 	{ SOCKS5_ERR_SELECTION,		FETCH_ABORT,	"SOCKS5: Failed to send selection method" },
114 	{ SOCKS5_ERR_READ_METHOD,	FETCH_ABORT,	"SOCKS5: Failed to read method" },
115 	{ SOCKS5_ERR_VER5_ONLY,		FETCH_PROTO,	"SOCKS5: Only version 5 is implemented" },
116 	{ SOCKS5_ERR_NOMETHODS,		FETCH_PROTO,	"SOCKS5: No acceptable methods" },
117 	{ SOCKS5_ERR_NOTIMPLEMENTED,	FETCH_PROTO,	"SOCKS5: Method currently not implemented" },
118 	{ SOCKS5_ERR_HOSTNAME_SIZE,	FETCH_PROTO,	"SOCKS5: Hostname size is above 256 bytes" },
119 	{ SOCKS5_ERR_REQUEST,		FETCH_PROTO,	"SOCKS5: Failed to request" },
120 	{ SOCKS5_ERR_REPLY,		FETCH_PROTO,	"SOCKS5: Failed to receive reply" },
121 	{ SOCKS5_ERR_NON_VER5_RESP,	FETCH_PROTO,	"SOCKS5: Server responded with a non-version 5 response" },
122 	{ SOCKS5_ERR_GENERAL,		FETCH_ABORT,	"SOCKS5: General server failure" },
123 	{ SOCKS5_ERR_NOT_ALLOWED,	FETCH_AUTH,	"SOCKS5: Connection not allowed by ruleset" },
124 	{ SOCKS5_ERR_NET_UNREACHABLE,	FETCH_NETWORK,	"SOCKS5: Network unreachable" },
125 	{ SOCKS5_ERR_HOST_UNREACHABLE,	FETCH_ABORT,	"SOCKS5: Host unreachable" },
126 	{ SOCKS5_ERR_CONN_REFUSED,	FETCH_ABORT,	"SOCKS5: Connection refused" },
127 	{ SOCKS5_ERR_TTL_EXPIRED,	FETCH_TIMEOUT,	"SOCKS5: TTL expired" },
128 	{ SOCKS5_ERR_COM_UNSUPPORTED,	FETCH_PROTO,	"SOCKS5: Command not supported" },
129 	{ SOCKS5_ERR_ADDR_UNSUPPORTED,	FETCH_ABORT,	"SOCKS5: Address type not supported" },
130 	{ SOCKS5_ERR_UNSPECIFIED,	FETCH_UNKNOWN,	"SOCKS5: Unspecified error" },
131 /* Configuration error */
132 	{ SOCKS5_ERR_BAD_HOST,		FETCH_ABORT,	"SOCKS5: Bad proxy host" },
133 	{ SOCKS5_ERR_BAD_PROXY_FORMAT,	FETCH_ABORT,	"SOCKS5: Bad proxy format" },
134 	{ SOCKS5_ERR_BAD_PORT,		FETCH_ABORT,	"SOCKS5: Bad port" }
135 };
136 
137 /* End-of-Line */
138 static const char ENDL[2] = { '\r', '\n' };
139 
140 
141 /*** Error-reporting functions ***********************************************/
142 
143 /*
144  * Map error code to string
145  */
146 static struct fetcherr *
147 fetch_finderr(struct fetcherr *p, int e)
148 {
149 	while (p->num != -1 && p->num != e)
150 		p++;
151 	return (p);
152 }
153 
154 /*
155  * Set error code
156  */
157 void
158 fetch_seterr(struct fetcherr *p, int e)
159 {
160 	p = fetch_finderr(p, e);
161 	fetchLastErrCode = p->cat;
162 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", p->string);
163 }
164 
165 /*
166  * Set error code according to errno
167  */
168 void
169 fetch_syserr(void)
170 {
171 	switch (errno) {
172 	case 0:
173 		fetchLastErrCode = FETCH_OK;
174 		break;
175 	case EPERM:
176 	case EACCES:
177 	case EROFS:
178 	case EAUTH:
179 	case ENEEDAUTH:
180 		fetchLastErrCode = FETCH_AUTH;
181 		break;
182 	case ENOENT:
183 	case EISDIR: /* XXX */
184 		fetchLastErrCode = FETCH_UNAVAIL;
185 		break;
186 	case ENOMEM:
187 		fetchLastErrCode = FETCH_MEMORY;
188 		break;
189 	case EBUSY:
190 	case EAGAIN:
191 		fetchLastErrCode = FETCH_TEMP;
192 		break;
193 	case EEXIST:
194 		fetchLastErrCode = FETCH_EXISTS;
195 		break;
196 	case ENOSPC:
197 		fetchLastErrCode = FETCH_FULL;
198 		break;
199 	case EADDRINUSE:
200 	case EADDRNOTAVAIL:
201 	case ENETDOWN:
202 	case ENETUNREACH:
203 	case ENETRESET:
204 	case EHOSTUNREACH:
205 		fetchLastErrCode = FETCH_NETWORK;
206 		break;
207 	case ECONNABORTED:
208 	case ECONNRESET:
209 		fetchLastErrCode = FETCH_ABORT;
210 		break;
211 	case ETIMEDOUT:
212 		fetchLastErrCode = FETCH_TIMEOUT;
213 		break;
214 	case ECONNREFUSED:
215 	case EHOSTDOWN:
216 		fetchLastErrCode = FETCH_DOWN;
217 		break;
218 	default:
219 		fetchLastErrCode = FETCH_UNKNOWN;
220 	}
221 	snprintf(fetchLastErrString, MAXERRSTRING, "%s", strerror(errno));
222 }
223 
224 
225 /*
226  * Emit status message
227  */
228 void
229 fetch_info(const char *fmt, ...)
230 {
231 	va_list ap;
232 	int serrno = errno;
233 
234 	va_start(ap, fmt);
235 	vfprintf(stderr, fmt, ap);
236 	va_end(ap);
237 	fputc('\n', stderr);
238 	errno = serrno;
239 }
240 #define fetch_verbose(...)						\
241 	do { if (verbose) fetch_info(__VA_ARGS__); } while (0)
242 
243 
244 /*** Network-related utility functions ***************************************/
245 
246 /*
247  * Return the default port for a scheme
248  */
249 int
250 fetch_default_port(const char *scheme)
251 {
252 	struct servent *se;
253 
254 	if ((se = getservbyname(scheme, "tcp")) != NULL)
255 		return (ntohs(se->s_port));
256 	if (strcmp(scheme, SCHEME_FTP) == 0)
257 		return (FTP_DEFAULT_PORT);
258 	if (strcmp(scheme, SCHEME_HTTP) == 0)
259 		return (HTTP_DEFAULT_PORT);
260 	return (0);
261 }
262 
263 /*
264  * Return the default proxy port for a scheme
265  */
266 int
267 fetch_default_proxy_port(const char *scheme)
268 {
269 	if (strcmp(scheme, SCHEME_FTP) == 0)
270 		return (FTP_DEFAULT_PROXY_PORT);
271 	if (strcmp(scheme, SCHEME_HTTP) == 0)
272 		return (HTTP_DEFAULT_PROXY_PORT);
273 	return (0);
274 }
275 
276 
277 /*
278  * Create a connection for an existing descriptor.
279  */
280 conn_t *
281 fetch_reopen(int sd)
282 {
283 	conn_t *conn;
284 	int flags;
285 	int opt = 1;
286 
287 	/* allocate and fill connection structure */
288 	if ((conn = calloc(1, sizeof(*conn))) == NULL)
289 		return (NULL);
290 	flags = fcntl(sd, F_GETFD);
291 	if (flags != -1 && (flags & FD_CLOEXEC) == 0)
292 		(void)fcntl(sd, F_SETFD, flags | FD_CLOEXEC);
293 	flags = fcntl(sd, F_GETFL);
294 	if (flags != -1 && (flags & O_NONBLOCK) == 0)
295 		(void)fcntl(sd, F_SETFL, flags | O_NONBLOCK);
296 	(void)setsockopt(sd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
297 	conn->sd = sd;
298 	++conn->ref;
299 	return (conn);
300 }
301 
302 
303 /*
304  * Resolve an address
305  */
306 struct addrinfo *
307 fetch_resolve(const char *addr, int port, int af)
308 {
309 	char hbuf[256], sbuf[8];
310 	struct addrinfo hints, *res;
311 	const char *hb, *he, *sep;
312 	const char *host, *service;
313 	int err, len;
314 
315 	/* first, check for a bracketed IPv6 address */
316 	if (*addr == '[') {
317 		hb = addr + 1;
318 		if ((sep = strchr(hb, ']')) == NULL) {
319 			errno = EINVAL;
320 			goto syserr;
321 		}
322 		he = sep++;
323 	} else {
324 		hb = addr;
325 		sep = strchrnul(hb, ':');
326 		he = sep;
327 	}
328 
329 	/* see if we need to copy the host name */
330 	if (*he != '\0') {
331 		len = snprintf(hbuf, sizeof(hbuf),
332 		    "%.*s", (int)(he - hb), hb);
333 		if (len < 0)
334 			goto syserr;
335 		if (len >= (int)sizeof(hbuf)) {
336 			errno = ENAMETOOLONG;
337 			goto syserr;
338 		}
339 		host = hbuf;
340 	} else {
341 		host = hb;
342 	}
343 
344 	/* was it followed by a service name? */
345 	if (*sep == '\0' && port != 0) {
346 		if (port < 1 || port > 65535) {
347 			errno = EINVAL;
348 			goto syserr;
349 		}
350 		if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0)
351 			goto syserr;
352 		service = sbuf;
353 	} else if (*sep != '\0') {
354 		service = sep + 1;
355 	} else {
356 		service = NULL;
357 	}
358 
359 	/* resolve */
360 	memset(&hints, 0, sizeof(hints));
361 	hints.ai_family = af;
362 	hints.ai_socktype = SOCK_STREAM;
363 	hints.ai_flags = AI_ADDRCONFIG;
364 	if ((err = getaddrinfo(host, service, &hints, &res)) != 0) {
365 		netdb_seterr(err);
366 		return (NULL);
367 	}
368 	return (res);
369 syserr:
370 	fetch_syserr();
371 	return (NULL);
372 }
373 
374 
375 /*
376  * Bind a socket to a specific local address
377  */
378 int
379 fetch_bind(int sd, int af, const char *addr)
380 {
381 	struct addrinfo *cliai, *ai;
382 	int err;
383 
384 	if ((cliai = fetch_resolve(addr, 0, af)) == NULL)
385 		return (-1);
386 	for (ai = cliai; ai != NULL; ai = ai->ai_next)
387 		if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0)
388 			break;
389 	if (err != 0)
390 		fetch_syserr();
391 	freeaddrinfo(cliai);
392 	return (err == 0 ? 0 : -1);
393 }
394 
395 
396 /*
397  * SOCKS5 connection initiation, based on RFC 1928
398  * Default DNS resolution over SOCKS5
399  */
400 int
401 fetch_socks5_init(conn_t *conn, const char *host, int port, int verbose)
402 {
403 	/*
404 	 * Size is based on largest packet prefix (4 bytes) +
405 	 * Largest FQDN (256) + one byte size (1) +
406 	 * Port (2)
407 	 */
408 	unsigned char buf[BUFF_SIZE];
409 	unsigned char *ptr;
410 	int ret = 1;
411 
412 	fetch_verbose("Initializing SOCKS5 connection: %s:%d", host, port);
413 
414 	/* Connection initialization */
415 	ptr = buf;
416 	*ptr++ = SOCKS_VERSION_5;
417 	*ptr++ = SOCKS_CONNECTION;
418 	*ptr++ = SOCKS_RSV;
419 
420 	if (fetch_write(conn, buf, 3) != 3) {
421 		ret = SOCKS5_ERR_SELECTION;
422 		goto fail;
423 	}
424 
425 	/* Verify response from SOCKS5 server */
426 	if (fetch_read(conn, buf, 2) != 2) {
427 		ret = SOCKS5_ERR_READ_METHOD;
428 		goto fail;
429 	}
430 
431 	ptr = buf;
432 	if (ptr[0] != SOCKS_VERSION_5) {
433 		ret = SOCKS5_ERR_VER5_ONLY;
434 		goto fail;
435 	}
436 	if (ptr[1] == SOCKS_NOMETHODS) {
437 		ret = SOCKS5_ERR_NOMETHODS;
438 		goto fail;
439 	}
440 	else if (ptr[1] != SOCKS5_NOTIMPLEMENTED) {
441 		ret = SOCKS5_ERR_NOTIMPLEMENTED;
442 		goto fail;
443 	}
444 
445 	/* Send Request */
446 	*ptr++ = SOCKS_VERSION_5;
447 	*ptr++ = SOCKS_CONNECTION;
448 	*ptr++ = SOCKS_RSV;
449 	/* Encode all targets as a hostname to avoid DNS leaks */
450 	*ptr++ = SOCKS_ATYP_DOMAINNAME;
451 	if (strlen(host) > FQDN_SIZE) {
452 		ret = SOCKS5_ERR_HOSTNAME_SIZE;
453 		goto fail;
454 	}
455 	*ptr++ = strlen(host);
456 	memcpy(ptr, host, strlen(host));
457 	ptr = ptr + strlen(host);
458 
459 	port = htons(port);
460 	*ptr++ = port & 0x00ff;
461 	*ptr++ = (port & 0xff00) >> 8;
462 
463 	if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
464 		ret = SOCKS5_ERR_REQUEST;
465 		goto fail;
466 	}
467 
468 	/* BND.ADDR is variable length, read the largest on non-blocking socket */
469 	if (!fetch_read(conn, buf, BUFF_SIZE)) {
470 		ret = SOCKS5_ERR_REPLY;
471 		goto fail;
472 	}
473 
474 	ptr = buf;
475 	if (*ptr++ != SOCKS_VERSION_5) {
476 		ret = SOCKS5_ERR_NON_VER5_RESP;
477 		goto fail;
478 	}
479 
480 	switch (*ptr++) {
481 	case SOCKS_SUCCESS:
482 		break;
483 	case SOCKS_GENERAL_FAILURE:
484 		ret = SOCKS5_ERR_GENERAL;
485 		goto fail;
486 	case SOCKS_CONNECTION_NOT_ALLOWED:
487 		ret = SOCKS5_ERR_NOT_ALLOWED;
488 		goto fail;
489 	case SOCKS_NETWORK_UNREACHABLE:
490 		ret = SOCKS5_ERR_NET_UNREACHABLE;
491 		goto fail;
492 	case SOCKS_HOST_UNREACHABLE:
493 		ret = SOCKS5_ERR_HOST_UNREACHABLE;
494 		goto fail;
495 	case SOCKS_CONNECTION_REFUSED:
496 		ret = SOCKS5_ERR_CONN_REFUSED;
497 		goto fail;
498 	case SOCKS_TTL_EXPIRED:
499 		ret = SOCKS5_ERR_TTL_EXPIRED;
500 		goto fail;
501 	case SOCKS_COMMAND_NOT_SUPPORTED:
502 		ret = SOCKS5_ERR_COM_UNSUPPORTED;
503 		goto fail;
504 	case SOCKS_ADDRESS_NOT_SUPPORTED:
505 		ret = SOCKS5_ERR_ADDR_UNSUPPORTED;
506 		goto fail;
507 	default:
508 		ret = SOCKS5_ERR_UNSPECIFIED;
509 		goto fail;
510 	}
511 
512 	return (ret);
513 
514 fail:
515 	socks5_seterr(ret);
516 	return (0);
517 }
518 
519 /*
520  * Perform SOCKS5 initialization
521  */
522 int
523 fetch_socks5_getenv(char **host, int *port)
524 {
525 	char *socks5env, *endptr, *ext;
526 	const char *portDelim;
527 	size_t slen;
528 
529 	portDelim = ":";
530 	if ((socks5env = getenv("SOCKS5_PROXY")) == NULL || *socks5env == '\0') {
531 		*host = NULL;
532 		*port = -1;
533 		return (-1);
534 	}
535 
536 	/*
537 	 * IPv6 addresses begin and end in brackets.  Set the port delimiter
538 	 * accordingly and search for it so we can do appropriate validation.
539 	 */
540 	if (socks5env[0] == '[')
541 		portDelim = "]:";
542 
543 	slen = strlen(socks5env);
544 	ext = strstr(socks5env, portDelim);
545 	if (socks5env[0] == '[') {
546 		if (socks5env[slen - 1] == ']') {
547 			*host = strndup(socks5env, slen);
548 		} else if (ext != NULL) {
549 			*host = strndup(socks5env, ext - socks5env + 1);
550 		} else {
551 			socks5_seterr(SOCKS5_ERR_BAD_PROXY_FORMAT);
552 			return (0);
553 		}
554 	} else {
555 		*host = strndup(socks5env, ext - socks5env);
556 	}
557 
558 	if (*host == NULL)
559 		return (-1);
560 	if (ext == NULL) {
561 		*port = 1080; /* Default port as defined in RFC1928 */
562 	} else {
563 		ext += strlen(portDelim);
564 		errno = 0;
565 		*port = strtoimax(ext, (char **)&endptr, 10);
566 		if (*endptr != '\0' || errno != 0 || *port < 0 ||
567 		    *port > 65535) {
568 			free(*host);
569 			*host = NULL;
570 			socks5_seterr(SOCKS5_ERR_BAD_PORT);
571 			return (0);
572 		}
573 	}
574 
575 	return (2);
576 }
577 
578 
579 /*
580  * Establish a TCP connection to the specified port on the specified host.
581  */
582 conn_t *
583 fetch_connect(const char *host, int port, int af, int verbose)
584 {
585 	struct timeval now, timeout, delta;
586 	struct pollfd pfd;
587 	struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai;
588 	const char *bindaddr;
589 	conn_t *conn = NULL;
590 	int err = 0, sd = -1;
591 	int deltams;
592 	char *sockshost;
593 	int socksport;
594 
595 	DEBUGF("---> %s:%d\n", host, port);
596 
597 	/*
598 	 * Check if SOCKS5_PROXY env variable is set.  fetch_socks5_getenv
599 	 * will either set sockshost = NULL or allocate memory in all cases.
600 	 */
601 	sockshost = NULL;
602 	if (!fetch_socks5_getenv(&sockshost, &socksport))
603 		goto fail;
604 
605 	/* Not using SOCKS5 proxy */
606 	if (sockshost == NULL) {
607 		/* resolve server address */
608 		fetch_verbose("resolving server address: %s:%d", host, port);
609 		if ((sais = fetch_resolve(host, port, af)) == NULL)
610 			goto fail;
611 
612 		/* resolve client address */
613 		bindaddr = getenv("FETCH_BIND_ADDRESS");
614 		if (bindaddr != NULL && *bindaddr != '\0') {
615 			fetch_verbose("resolving client address: %s", bindaddr);
616 			if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL)
617 				goto fail;
618 		}
619 	} else {
620 		/* resolve socks5 proxy address */
621 		fetch_verbose("resolving SOCKS5 server address: %s:%d",
622 		    sockshost, socksport);
623 		if ((sais = fetch_resolve(sockshost, socksport, af)) == NULL) {
624 			socks5_seterr(SOCKS5_ERR_BAD_HOST);
625 			goto fail;
626 		}
627 	}
628 
629 	/* try each server address in turn */
630 	for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) {
631 		/* open socket */
632 		if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0) {
633 			err = -1;
634 			if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT)
635 				continue;
636 			goto syserr;
637 		}
638 		/* attempt to bind to client address */
639 		for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) {
640 			if (cai->ai_family != sai->ai_family)
641 				continue;
642 			if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0)
643 				break;
644 		}
645 		if (err != 0) {
646 			fetch_verbose("failed to bind to %s", bindaddr);
647 			goto syserr;
648 		}
649 		/* make the socket non-blocking */
650 		(void)fcntl(sd, F_SETFL, O_NONBLOCK);
651 		/* start the clock */
652 		if (fetchTimeout > 0) {
653 			gettimeofday(&timeout, NULL);
654 			timeout.tv_sec += fetchTimeout;
655 			deltams = fetchTimeout * 1000;
656 		}
657 		/* attempt to connect to server address */
658 		if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0)
659 			break;
660 		/* wait for connection */
661 		if (errno == EINPROGRESS) {
662 			deltams = INFTIM;
663 			pfd.fd = sd;
664 			pfd.events = POLLOUT;
665 			for (;;) {
666 				/* wait for something to happen */
667 				if (poll(&pfd, 1, deltams) >= 0)
668 					break;
669 				if (errno == EINTR && !fetchRestartCalls)
670 					break;
671 				/* check the clock */
672 				if (fetchTimeout > 0) {
673 					gettimeofday(&now, NULL);
674 					if (!timercmp(&timeout, &now, >)) {
675 						errno = ETIMEDOUT;
676 						pfd.revents = POLLERR;
677 						break;
678 					}
679 					timersub(&timeout, &now, &delta);
680 					deltams = delta.tv_sec * 1000 +
681 					    delta.tv_usec / 1000;
682 				}
683 			}
684 			if (pfd.revents == POLLOUT) {
685 				/* connection established */
686 				err = 0;
687 				break;
688 			}
689 		}
690 		/* clean up before next attempt */
691 		close(sd);
692 		sd = -1;
693 	}
694 	if (err != 0) {
695 		if (verbose && sockshost == NULL) {
696 			fetch_info("failed to connect to %s:%d", host, port);
697 			goto syserr;
698 		} else if (sockshost != NULL) {
699 			fetch_verbose("failed to connect to SOCKS5 server %s:%d",
700 			    sockshost, socksport);
701 			socks5_seterr(SOCKS5_ERR_CONN_REFUSED);
702 			goto fail;
703 		}
704 		goto syserr;
705 	}
706 
707 	if ((conn = fetch_reopen(sd)) == NULL)
708 		goto syserr;
709 
710 	if (sockshost)
711 		if (!fetch_socks5_init(conn, host, port, verbose))
712 			goto fail;
713 	free(sockshost);
714 	if (cais != NULL)
715 		freeaddrinfo(cais);
716 	if (sais != NULL)
717 		freeaddrinfo(sais);
718 	return (conn);
719 syserr:
720 	fetch_syserr();
721 fail:
722 	free(sockshost);
723 	/* Fully close if it was opened; otherwise just don't leak the fd. */
724 	if (conn != NULL)
725 		fetch_close(conn);
726 	else if (sd >= 0)
727 		close(sd);
728 	if (cais != NULL)
729 		freeaddrinfo(cais);
730 	if (sais != NULL)
731 		freeaddrinfo(sais);
732 	return (NULL);
733 }
734 
735 #ifdef WITH_SSL
736 /*
737  * Convert characters A-Z to lowercase (intentionally avoid any locale
738  * specific conversions).
739  */
740 static char
741 fetch_ssl_tolower(char in)
742 {
743 	if (in >= 'A' && in <= 'Z')
744 		return (in + 32);
745 	else
746 		return (in);
747 }
748 
749 /*
750  * isalpha implementation that intentionally avoids any locale specific
751  * conversions.
752  */
753 static int
754 fetch_ssl_isalpha(char in)
755 {
756 	return ((in >= 'A' && in <= 'Z') || (in >= 'a' && in <= 'z'));
757 }
758 
759 /*
760  * Check if passed hostnames a and b are equal.
761  */
762 static int
763 fetch_ssl_hname_equal(const char *a, size_t alen, const char *b,
764     size_t blen)
765 {
766 	size_t i;
767 
768 	if (alen != blen)
769 		return (0);
770 	for (i = 0; i < alen; ++i) {
771 		if (fetch_ssl_tolower(a[i]) != fetch_ssl_tolower(b[i]))
772 			return (0);
773 	}
774 	return (1);
775 }
776 
777 /*
778  * Check if domain label is traditional, meaning that only A-Z, a-z, 0-9
779  * and '-' (hyphen) are allowed. Hyphens have to be surrounded by alpha-
780  * numeric characters. Double hyphens (like they're found in IDN a-labels
781  * 'xn--') are not allowed. Empty labels are invalid.
782  */
783 static int
784 fetch_ssl_is_trad_domain_label(const char *l, size_t len, int wcok)
785 {
786 	size_t i;
787 
788 	if (!len || l[0] == '-' || l[len-1] == '-')
789 		return (0);
790 	for (i = 0; i < len; ++i) {
791 		if (!isdigit(l[i]) &&
792 		    !fetch_ssl_isalpha(l[i]) &&
793 		    !(l[i] == '*' && wcok) &&
794 		    !(l[i] == '-' && l[i - 1] != '-'))
795 			return (0);
796 	}
797 	return (1);
798 }
799 
800 /*
801  * Check if host name consists only of numbers. This might indicate an IP
802  * address, which is not a good idea for CN wildcard comparison.
803  */
804 static int
805 fetch_ssl_hname_is_only_numbers(const char *hostname, size_t len)
806 {
807 	size_t i;
808 
809 	for (i = 0; i < len; ++i) {
810 		if (!((hostname[i] >= '0' && hostname[i] <= '9') ||
811 		    hostname[i] == '.'))
812 			return (0);
813 	}
814 	return (1);
815 }
816 
817 /*
818  * Check if the host name h passed matches the pattern passed in m which
819  * is usually part of subjectAltName or CN of a certificate presented to
820  * the client. This includes wildcard matching. The algorithm is based on
821  * RFC6125, sections 6.4.3 and 7.2, which clarifies RFC2818 and RFC3280.
822  */
823 static int
824 fetch_ssl_hname_match(const char *h, size_t hlen, const char *m,
825     size_t mlen)
826 {
827 	int delta, hdotidx, mdot1idx, wcidx;
828 	const char *hdot, *mdot1, *mdot2;
829 	const char *wc; /* wildcard */
830 
831 	if (!(h && *h && m && *m))
832 		return (0);
833 	if ((wc = strnstr(m, "*", mlen)) == NULL)
834 		return (fetch_ssl_hname_equal(h, hlen, m, mlen));
835 	wcidx = wc - m;
836 	/* hostname should not be just dots and numbers */
837 	if (fetch_ssl_hname_is_only_numbers(h, hlen))
838 		return (0);
839 	/* only one wildcard allowed in pattern */
840 	if (strnstr(wc + 1, "*", mlen - wcidx - 1) != NULL)
841 		return (0);
842 	/*
843 	 * there must be at least two more domain labels and
844 	 * wildcard has to be in the leftmost label (RFC6125)
845 	 */
846 	mdot1 = strnstr(m, ".", mlen);
847 	if (mdot1 == NULL || mdot1 < wc || (mlen - (mdot1 - m)) < 4)
848 		return (0);
849 	mdot1idx = mdot1 - m;
850 	mdot2 = strnstr(mdot1 + 1, ".", mlen - mdot1idx - 1);
851 	if (mdot2 == NULL || (mlen - (mdot2 - m)) < 2)
852 		return (0);
853 	/* hostname must contain a dot and not be the 1st char */
854 	hdot = strnstr(h, ".", hlen);
855 	if (hdot == NULL || hdot == h)
856 		return (0);
857 	hdotidx = hdot - h;
858 	/*
859 	 * host part of hostname must be at least as long as
860 	 * pattern it's supposed to match
861 	 */
862 	if (hdotidx < mdot1idx)
863 		return (0);
864 	/*
865 	 * don't allow wildcards in non-traditional domain names
866 	 * (IDN, A-label, U-label...)
867 	 */
868 	if (!fetch_ssl_is_trad_domain_label(h, hdotidx, 0) ||
869 	    !fetch_ssl_is_trad_domain_label(m, mdot1idx, 1))
870 		return (0);
871 	/* match domain part (part after first dot) */
872 	if (!fetch_ssl_hname_equal(hdot, hlen - hdotidx, mdot1,
873 	    mlen - mdot1idx))
874 		return (0);
875 	/* match part left of wildcard */
876 	if (!fetch_ssl_hname_equal(h, wcidx, m, wcidx))
877 		return (0);
878 	/* match part right of wildcard */
879 	delta = mdot1idx - wcidx - 1;
880 	if (!fetch_ssl_hname_equal(hdot - delta, delta,
881 	    mdot1 - delta, delta))
882 		return (0);
883 	/* all tests succeeded, it's a match */
884 	return (1);
885 }
886 
887 /*
888  * Get numeric host address info - returns NULL if host was not an IP
889  * address. The caller is responsible for deallocation using
890  * freeaddrinfo(3).
891  */
892 static struct addrinfo *
893 fetch_ssl_get_numeric_addrinfo(const char *hostname, size_t len)
894 {
895 	struct addrinfo hints, *res;
896 	char *host;
897 
898 	host = (char *)malloc(len + 1);
899 	memcpy(host, hostname, len);
900 	host[len] = '\0';
901 	memset(&hints, 0, sizeof(hints));
902 	hints.ai_family = PF_UNSPEC;
903 	hints.ai_socktype = SOCK_STREAM;
904 	hints.ai_protocol = 0;
905 	hints.ai_flags = AI_NUMERICHOST;
906 	/* port is not relevant for this purpose */
907 	if (getaddrinfo(host, "443", &hints, &res) != 0)
908 		res = NULL;
909 	free(host);
910 	return res;
911 }
912 
913 /*
914  * Compare ip address in addrinfo with address passes.
915  */
916 static int
917 fetch_ssl_ipaddr_match_bin(const struct addrinfo *lhost, const char *rhost,
918     size_t rhostlen)
919 {
920 	const void *left;
921 
922 	if (lhost->ai_family == AF_INET && rhostlen == 4) {
923 		left = (void *)&((struct sockaddr_in*)(void *)
924 		    lhost->ai_addr)->sin_addr.s_addr;
925 #ifdef INET6
926 	} else if (lhost->ai_family == AF_INET6 && rhostlen == 16) {
927 		left = (void *)&((struct sockaddr_in6 *)(void *)
928 		    lhost->ai_addr)->sin6_addr;
929 #endif
930 	} else
931 		return (0);
932 	return (!memcmp(left, (const void *)rhost, rhostlen) ? 1 : 0);
933 }
934 
935 /*
936  * Compare ip address in addrinfo with host passed. If host is not an IP
937  * address, comparison will fail.
938  */
939 static int
940 fetch_ssl_ipaddr_match(const struct addrinfo *laddr, const char *r,
941     size_t rlen)
942 {
943 	struct addrinfo *raddr;
944 	int ret;
945 	char *rip;
946 
947 	ret = 0;
948 	if ((raddr = fetch_ssl_get_numeric_addrinfo(r, rlen)) == NULL)
949 		return 0; /* not a numeric host */
950 
951 	if (laddr->ai_family == raddr->ai_family) {
952 		if (laddr->ai_family == AF_INET) {
953 			rip = (char *)&((struct sockaddr_in *)(void *)
954 			    raddr->ai_addr)->sin_addr.s_addr;
955 			ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 4);
956 #ifdef INET6
957 		} else if (laddr->ai_family == AF_INET6) {
958 			rip = (char *)&((struct sockaddr_in6 *)(void *)
959 			    raddr->ai_addr)->sin6_addr;
960 			ret = fetch_ssl_ipaddr_match_bin(laddr, rip, 16);
961 #endif
962 		}
963 
964 	}
965 	freeaddrinfo(raddr);
966 	return (ret);
967 }
968 
969 /*
970  * Verify server certificate by subjectAltName.
971  */
972 static int
973 fetch_ssl_verify_altname(STACK_OF(GENERAL_NAME) *altnames,
974     const char *host, struct addrinfo *ip)
975 {
976 	const GENERAL_NAME *name;
977 	size_t nslen;
978 	int i;
979 	const char *ns;
980 
981 	for (i = 0; i < sk_GENERAL_NAME_num(altnames); ++i) {
982 		name = sk_GENERAL_NAME_value(altnames, i);
983 		ns = (const char *)ASN1_STRING_get0_data(name->d.ia5);
984 		nslen = (size_t)ASN1_STRING_length(name->d.ia5);
985 
986 		if (name->type == GEN_DNS && ip == NULL &&
987 		    fetch_ssl_hname_match(host, strlen(host), ns, nslen))
988 			return (1);
989 		else if (name->type == GEN_IPADD && ip != NULL &&
990 		    fetch_ssl_ipaddr_match_bin(ip, ns, nslen))
991 			return (1);
992 	}
993 	return (0);
994 }
995 
996 /*
997  * Verify server certificate by CN.
998  */
999 static int
1000 fetch_ssl_verify_cn(X509_NAME *subject, const char *host,
1001     struct addrinfo *ip)
1002 {
1003 	ASN1_STRING *namedata;
1004 	X509_NAME_ENTRY *nameentry;
1005 	int cnlen, lastpos, loc, ret;
1006 	unsigned char *cn;
1007 
1008 	ret = 0;
1009 	lastpos = -1;
1010 	loc = -1;
1011 	cn = NULL;
1012 	/* get most specific CN (last entry in list) and compare */
1013 	while ((lastpos = X509_NAME_get_index_by_NID(subject,
1014 	    NID_commonName, lastpos)) != -1)
1015 		loc = lastpos;
1016 
1017 	if (loc > -1) {
1018 		nameentry = X509_NAME_get_entry(subject, loc);
1019 		namedata = X509_NAME_ENTRY_get_data(nameentry);
1020 		cnlen = ASN1_STRING_to_UTF8(&cn, namedata);
1021 		if (ip == NULL &&
1022 		    fetch_ssl_hname_match(host, strlen(host), cn, cnlen))
1023 			ret = 1;
1024 		else if (ip != NULL && fetch_ssl_ipaddr_match(ip, cn, cnlen))
1025 			ret = 1;
1026 		OPENSSL_free(cn);
1027 	}
1028 	return (ret);
1029 }
1030 
1031 /*
1032  * Verify that server certificate subjectAltName/CN matches
1033  * hostname. First check, if there are alternative subject names. If yes,
1034  * those have to match. Only if those don't exist it falls back to
1035  * checking the subject's CN.
1036  */
1037 static int
1038 fetch_ssl_verify_hname(X509 *cert, const char *host)
1039 {
1040 	struct addrinfo *ip;
1041 	STACK_OF(GENERAL_NAME) *altnames;
1042 	X509_NAME *subject;
1043 	int ret;
1044 
1045 	ret = 0;
1046 	ip = fetch_ssl_get_numeric_addrinfo(host, strlen(host));
1047 	altnames = X509_get_ext_d2i(cert, NID_subject_alt_name,
1048 	    NULL, NULL);
1049 
1050 	if (altnames != NULL) {
1051 		ret = fetch_ssl_verify_altname(altnames, host, ip);
1052 	} else {
1053 		subject = X509_get_subject_name(cert);
1054 		if (subject != NULL)
1055 			ret = fetch_ssl_verify_cn(subject, host, ip);
1056 	}
1057 
1058 	if (ip != NULL)
1059 		freeaddrinfo(ip);
1060 	if (altnames != NULL)
1061 		GENERAL_NAMES_free(altnames);
1062 	return (ret);
1063 }
1064 
1065 /*
1066  * Configure transport security layer based on environment.
1067  */
1068 static void
1069 fetch_ssl_setup_transport_layer(SSL_CTX *ctx, int verbose)
1070 {
1071 	long ssl_ctx_options;
1072 
1073 	ssl_ctx_options = SSL_OP_ALL | SSL_OP_NO_SSLv3 | SSL_OP_NO_TICKET;
1074 	if (getenv("SSL_NO_TLS1") != NULL)
1075 		ssl_ctx_options |= SSL_OP_NO_TLSv1;
1076 	if (getenv("SSL_NO_TLS1_1") != NULL)
1077 		ssl_ctx_options |= SSL_OP_NO_TLSv1_1;
1078 	if (getenv("SSL_NO_TLS1_2") != NULL)
1079 		ssl_ctx_options |= SSL_OP_NO_TLSv1_2;
1080 	if (getenv("SSL_NO_TLS1_3") != NULL)
1081 		ssl_ctx_options |= SSL_OP_NO_TLSv1_3;
1082 	fetch_verbose("SSL options: %lx", ssl_ctx_options);
1083 	SSL_CTX_set_options(ctx, ssl_ctx_options);
1084 }
1085 
1086 
1087 /*
1088  * Configure peer verification based on environment.
1089  */
1090 static int
1091 fetch_ssl_setup_peer_verification(SSL_CTX *ctx, int verbose)
1092 {
1093 	X509_LOOKUP *crl_lookup;
1094 	X509_STORE *crl_store;
1095 	const char *ca_cert_file, *ca_cert_path, *crl_file;
1096 
1097 	if (getenv("SSL_NO_VERIFY_PEER") == NULL) {
1098 		ca_cert_file = getenv("SSL_CA_CERT_FILE");
1099 		ca_cert_path = getenv("SSL_CA_CERT_PATH");
1100 		if (verbose) {
1101 			fetch_info("Peer verification enabled");
1102 			if (ca_cert_file != NULL)
1103 				fetch_info("Using CA cert file: %s",
1104 				    ca_cert_file);
1105 			if (ca_cert_path != NULL)
1106 				fetch_info("Using CA cert path: %s",
1107 				    ca_cert_path);
1108 			if (ca_cert_file == NULL && ca_cert_path == NULL)
1109 				fetch_info("Using OpenSSL default "
1110 				    "CA cert file and path");
1111 		}
1112 		SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER,
1113 		    fetch_ssl_cb_verify_crt);
1114 		if (ca_cert_file != NULL || ca_cert_path != NULL)
1115 			SSL_CTX_load_verify_locations(ctx, ca_cert_file,
1116 			    ca_cert_path);
1117 		else
1118 			SSL_CTX_set_default_verify_paths(ctx);
1119 		if ((crl_file = getenv("SSL_CRL_FILE")) != NULL) {
1120 			fetch_verbose("Using CRL file: %s", crl_file);
1121 			crl_store = SSL_CTX_get_cert_store(ctx);
1122 			crl_lookup = X509_STORE_add_lookup(crl_store,
1123 			    X509_LOOKUP_file());
1124 			if (crl_lookup == NULL ||
1125 			    !X509_load_crl_file(crl_lookup, crl_file,
1126 				X509_FILETYPE_PEM)) {
1127 				fetch_info("Could not load CRL file %s",
1128 				    crl_file);
1129 				return (0);
1130 			}
1131 			X509_STORE_set_flags(crl_store,
1132 			    X509_V_FLAG_CRL_CHECK |
1133 			    X509_V_FLAG_CRL_CHECK_ALL);
1134 		}
1135 	}
1136 	return (1);
1137 }
1138 
1139 /*
1140  * Configure client certificate based on environment.
1141  */
1142 static int
1143 fetch_ssl_setup_client_certificate(SSL_CTX *ctx, int verbose)
1144 {
1145 	const char *client_cert_file, *client_key_file;
1146 
1147 	if ((client_cert_file = getenv("SSL_CLIENT_CERT_FILE")) != NULL) {
1148 		client_key_file = getenv("SSL_CLIENT_KEY_FILE") != NULL ?
1149 		    getenv("SSL_CLIENT_KEY_FILE") : client_cert_file;
1150 		fetch_verbose("Using client cert file: %s", client_cert_file);
1151 		fetch_verbose("Using client key file: %s", client_key_file);
1152 		if (SSL_CTX_use_certificate_chain_file(ctx,
1153 			client_cert_file) != 1) {
1154 			fetch_info("Could not load client certificate %s",
1155 			    client_cert_file);
1156 			return (0);
1157 		}
1158 		if (SSL_CTX_use_PrivateKey_file(ctx, client_key_file,
1159 			SSL_FILETYPE_PEM) != 1) {
1160 			fetch_info("Could not load client key %s",
1161 			    client_key_file);
1162 			return (0);
1163 		}
1164 	}
1165 	return (1);
1166 }
1167 
1168 /*
1169  * Callback for SSL certificate verification, this is called on server
1170  * cert verification. It takes no decision, but informs the user in case
1171  * verification failed.
1172  */
1173 int
1174 fetch_ssl_cb_verify_crt(int verified, X509_STORE_CTX *ctx)
1175 {
1176 	X509 *crt;
1177 	X509_NAME *name;
1178 	char *str;
1179 
1180 	str = NULL;
1181 	if (!verified) {
1182 		if ((crt = X509_STORE_CTX_get_current_cert(ctx)) != NULL &&
1183 		    (name = X509_get_subject_name(crt)) != NULL)
1184 			str = X509_NAME_oneline(name, 0, 0);
1185 		fetch_info("Certificate verification failed for %s",
1186 		    str != NULL ? str : "no relevant certificate");
1187 		OPENSSL_free(str);
1188 	}
1189 	return (verified);
1190 }
1191 
1192 #endif
1193 
1194 /*
1195  * Enable SSL on a connection.
1196  */
1197 int
1198 fetch_ssl(conn_t *conn, const struct url *URL, int verbose)
1199 {
1200 #ifdef WITH_SSL
1201 	int ret, ssl_err;
1202 	X509_NAME *name;
1203 	char *str;
1204 
1205 	if ((conn->ssl_ctx = SSL_CTX_new(TLS_client_method())) == NULL) {
1206 		fetch_info("SSL context creation failed");
1207 		ERR_print_errors_fp(stderr);
1208 		return (-1);
1209 	}
1210 	SSL_CTX_set_mode(conn->ssl_ctx, SSL_MODE_AUTO_RETRY);
1211 
1212 	fetch_ssl_setup_transport_layer(conn->ssl_ctx, verbose);
1213 	if (!fetch_ssl_setup_peer_verification(conn->ssl_ctx, verbose))
1214 		return (-1);
1215 	if (!fetch_ssl_setup_client_certificate(conn->ssl_ctx, verbose))
1216 		return (-1);
1217 
1218 	conn->ssl = SSL_new(conn->ssl_ctx);
1219 	if (conn->ssl == NULL) {
1220 		fetch_info("SSL connection creation failed");
1221 		ERR_print_errors_fp(stderr);
1222 		return (-1);
1223 	}
1224 	SSL_set_fd(conn->ssl, conn->sd);
1225 
1226 #if !defined(OPENSSL_NO_TLSEXT)
1227 	if (!SSL_set_tlsext_host_name(conn->ssl, __DECONST(char *, URL->host))) {
1228 		fetch_info("Failed to set TLS server name indication for host %s",
1229 		    URL->host);
1230 		return (-1);
1231 	}
1232 #endif
1233 	while ((ret = SSL_connect(conn->ssl)) == -1) {
1234 		ssl_err = SSL_get_error(conn->ssl, ret);
1235 		if (ssl_err != SSL_ERROR_WANT_READ &&
1236 		    ssl_err != SSL_ERROR_WANT_WRITE) {
1237 			ERR_print_errors_fp(stderr);
1238 			return (-1);
1239 		}
1240 	}
1241 	conn->ssl_cert = SSL_get_peer_certificate(conn->ssl);
1242 
1243 	if (conn->ssl_cert == NULL) {
1244 		fetch_info("No server SSL certificate");
1245 		return (-1);
1246 	}
1247 
1248 	if (getenv("SSL_NO_VERIFY_HOSTNAME") == NULL) {
1249 		fetch_verbose("Verify hostname");
1250 		if (!fetch_ssl_verify_hname(conn->ssl_cert, URL->host)) {
1251 			fetch_info("SSL certificate subject does not match host %s",
1252 			    URL->host);
1253 			return (-1);
1254 		}
1255 	}
1256 
1257 	if (verbose) {
1258 		fetch_info("%s connection established using %s",
1259 		    SSL_get_version(conn->ssl), SSL_get_cipher(conn->ssl));
1260 		name = X509_get_subject_name(conn->ssl_cert);
1261 		str = X509_NAME_oneline(name, 0, 0);
1262 		fetch_info("Certificate subject: %s", str);
1263 		OPENSSL_free(str);
1264 		name = X509_get_issuer_name(conn->ssl_cert);
1265 		str = X509_NAME_oneline(name, 0, 0);
1266 		fetch_info("Certificate issuer: %s", str);
1267 		OPENSSL_free(str);
1268 	}
1269 
1270 	return (0);
1271 #else
1272 	(void)conn;
1273 	(void)verbose;
1274 	(void)URL;
1275 	fetch_info("SSL support disabled");
1276 	return (-1);
1277 #endif
1278 }
1279 
1280 #ifdef WITH_SSL
1281 static ssize_t
1282 fetch_ssl_read(SSL *ssl, void *buf, size_t len)
1283 {
1284 	ssize_t rlen;
1285 	int ssl_err;
1286 
1287 	rlen = SSL_read(ssl, buf, len);
1288 	if (rlen < 0) {
1289 		ssl_err = SSL_get_error(ssl, rlen);
1290 		switch (ssl_err) {
1291 		case SSL_ERROR_ZERO_RETURN:
1292 			return (0);
1293 		case SSL_ERROR_WANT_READ:
1294 			errno = EAGAIN;
1295 			return (-1);
1296 		case SSL_ERROR_SYSCALL:
1297 			return (-1);
1298 		default:
1299 			errno = EPROTO;
1300 			return (-1);
1301 		}
1302 	}
1303 	return (rlen);
1304 }
1305 
1306 static ssize_t
1307 fetch_ssl_write(SSL *ssl, void *buf, size_t len)
1308 {
1309 	ssize_t wlen;
1310 	int ssl_err;
1311 
1312 	wlen = SSL_write(ssl, buf, len);
1313 	if (wlen < 0) {
1314 		ssl_err = SSL_get_error(ssl, wlen);
1315 		switch (ssl_err) {
1316 		case SSL_ERROR_ZERO_RETURN:
1317 			return (0);
1318 		case SSL_ERROR_WANT_WRITE:
1319 			errno = EAGAIN;
1320 			return (-1);
1321 		case SSL_ERROR_SYSCALL:
1322 			return (-1);
1323 		default:
1324 			errno = EPROTO;
1325 			return (-1);
1326 		}
1327 	}
1328 	return (wlen);
1329 }
1330 #endif
1331 
1332 /*
1333  * Read from a connection w/ timeout
1334  */
1335 ssize_t
1336 fetch_read(conn_t *conn, void *buf, size_t len)
1337 {
1338 	struct timeval now, timeout, delta;
1339 	struct pollfd pfd;
1340 	ssize_t rlen, total;
1341 	int deltams;
1342 
1343 	if (fetchTimeout > 0) {
1344 		gettimeofday(&timeout, NULL);
1345 		timeout.tv_sec += fetchTimeout;
1346 	}
1347 
1348 	deltams = INFTIM;
1349 	pfd.fd = conn->sd;
1350 	pfd.events = POLLIN;
1351 
1352 	total = 0;
1353 	for (;;) {
1354 		/*
1355 		 * The socket is non-blocking.  Instead of the canonical
1356 		 * poll() -> read(), we do the following:
1357 		 *
1358 		 * 1) call read() or SSL_read().
1359 		 * 2) if we received some data, return it.
1360 		 * 3) if read() or SSL_read() signaled EOF, return.
1361 		 * 4) if an error occurred, return -1.
1362 		 * 5) if we did not receive any data but we're not at EOF,
1363 		 *    call poll().
1364 		 *
1365 		 * In the SSL case, this is necessary because if we
1366 		 * receive a close notification, we have to call
1367 		 * SSL_read() one additional time after we've read
1368 		 * everything we received.
1369 		 *
1370 		 * In the non-SSL case, it may improve performance (very
1371 		 * slightly) when reading small amounts of data.
1372 		 */
1373 #ifdef WITH_SSL
1374 		if (conn->ssl != NULL)
1375 			rlen = fetch_ssl_read(conn->ssl, buf, len);
1376 		else
1377 #endif
1378 			rlen = read(conn->sd, buf, len);
1379 		if (rlen > 0) {
1380 			/* something was read */
1381 			total += rlen;
1382 			len -= rlen;
1383 			if (len == 0)
1384 				break;
1385 			/* a partial read is success */
1386 			break;
1387 		} else if (rlen == 0) {
1388 			/* connection closed */
1389 			break;
1390 		} else if (errno != EAGAIN) {
1391 			/* error */
1392 			if (errno == EINTR && fetchRestartCalls)
1393 				continue;
1394 			fetch_syserr();
1395 			break;
1396 		}
1397 		/* check what's left of our timeout */
1398 		if (fetchTimeout > 0) {
1399 			gettimeofday(&now, NULL);
1400 			if (!timercmp(&timeout, &now, >)) {
1401 				errno = ETIMEDOUT;
1402 				fetch_syserr();
1403 				return (-1);
1404 			}
1405 			timersub(&timeout, &now, &delta);
1406 			deltams = delta.tv_sec * 1000 +
1407 			    delta.tv_usec / 1000;
1408 		}
1409 		/* wait for the socket to become readable */
1410 		if (poll(&pfd, 1, deltams) < 0) {
1411 			if (errno == EAGAIN)
1412 				continue;
1413 			if (errno == EINTR && fetchRestartCalls)
1414 				continue;
1415 			break;
1416 		}
1417 	}
1418 	/* a partial read is success */
1419 	if (rlen < 0 && total == 0)
1420 		return (-1);
1421 	return (total);
1422 }
1423 
1424 
1425 /*
1426  * Read a line of text from a connection w/ timeout
1427  */
1428 #define MIN_BUF_SIZE 1024
1429 
1430 ssize_t
1431 fetch_getln(conn_t *conn)
1432 {
1433 	char *tmp;
1434 	size_t tmpsize;
1435 	ssize_t rlen;
1436 
1437 	/* allocate initial buffer */
1438 	if (conn->buf == NULL) {
1439 		if ((conn->buf = malloc(MIN_BUF_SIZE)) == NULL)
1440 			goto fail;
1441 		conn->line = conn->buf;
1442 		conn->bufsize = MIN_BUF_SIZE;
1443 		conn->buflen = 0;
1444 		conn->pos = 0;
1445 	}
1446 
1447 	/* look at the data we already have */
1448 	if (conn->pos < conn->buflen) {
1449 		conn->line = conn->buf + conn->pos;
1450 		while (conn->pos < conn->buflen)
1451 			if (conn->buf[conn->pos++] == '\n')
1452 				goto found;
1453 		/* reset for the upcoming memmove() */
1454 		conn->pos = conn->line - conn->buf;
1455 	}
1456 
1457 	/* move residual data up */
1458 	if (conn->buflen > 0) {
1459 		if (conn->pos < conn->buflen) {
1460 			memmove(conn->buf, conn->buf + conn->pos,
1461 			    conn->buflen - conn->pos);
1462 		}
1463 		conn->buflen -= conn->pos;
1464 		conn->pos -= conn->pos;
1465 		conn->line = conn->buf;
1466 	}
1467 
1468 	for (;;) {
1469 		/* read as much as we can right now */
1470 		rlen = fetch_read(conn, conn->buf + conn->buflen,
1471 		    conn->bufsize - conn->buflen - 1);
1472 		/* error */
1473 		if (rlen < 0)
1474 			goto fail;
1475 		/* advance and terminate */
1476 		conn->buflen += rlen;
1477 		conn->buf[conn->buflen] = '\0';
1478 		/* connection closed */
1479 		if (rlen == 0)
1480 			break;
1481 		/* look for a newline */
1482 		while (conn->pos < conn->buflen)
1483 			if (conn->buf[conn->pos++] == '\n')
1484 				goto found;
1485 		/* do we need a bigger buffer? */
1486 		if (conn->buflen > conn->bufsize / 2) {
1487 			tmp = conn->buf;
1488 			tmpsize = conn->bufsize * 2;
1489 			if ((tmp = realloc(tmp, tmpsize)) == NULL)
1490 				goto fail;
1491 			conn->line = conn->buf = tmp;
1492 			conn->bufsize = tmpsize;
1493 		}
1494 	}
1495 	/* connection closed, return what's left */
1496 	conn->pos = conn->buflen;
1497 found:
1498 	conn->linelen = (conn->buf + conn->pos) - conn->line;
1499 	if (conn->linelen > 0 && conn->line[conn->linelen - 1] == '\n')
1500 		conn->line[--conn->linelen] = '\0';
1501 	if (conn->linelen > 0 && conn->line[conn->linelen - 1] == '\r')
1502 		conn->line[--conn->linelen] = '\0';
1503 	DEBUGF("<<< %.*s\n", (int)conn->linelen, conn->line);
1504 	return (conn->linelen);
1505 fail:
1506 	conn->line = NULL;
1507 	conn->linelen = 0;
1508 	return (-1);
1509 }
1510 
1511 
1512 /*
1513  * Read from a connection, taking previously buffered data into account.
1514  */
1515 ssize_t
1516 fetch_bufread(conn_t *conn, void *buf, size_t len)
1517 {
1518 	ssize_t rlen;
1519 
1520 	/* avoid overflow */
1521 	if (len > SSIZE_MAX)
1522 		len = SSIZE_MAX;
1523 
1524 	/* allocate initial buffer */
1525 	if (conn->buf == NULL) {
1526 		conn->bufsize = MIN_BUF_SIZE;
1527 		while (conn->bufsize < len)
1528 			conn->bufsize *= 2;
1529 		if ((conn->buf = malloc(conn->bufsize)) == NULL)
1530 			return (-1);
1531 		conn->buflen = 0;
1532 		conn->pos = 0;
1533 	}
1534 	conn->line = NULL;
1535 	conn->linelen = 0;
1536 
1537 	/* return residual data first */
1538 	if (conn->buflen > conn->pos) {
1539 		if (len > conn->buflen - conn->pos)
1540 			rlen = conn->buflen - conn->pos;
1541 		else
1542 			rlen = len;
1543 		memcpy(buf, conn->buf + conn->pos, rlen);
1544 		conn->pos += rlen;
1545 		return (rlen);
1546 	}
1547 
1548 	return (fetch_read(conn, buf, len));
1549 }
1550 
1551 
1552 /*
1553  * Write to a connection w/ timeout
1554  */
1555 ssize_t
1556 fetch_write(conn_t *conn, const void *buf, size_t len)
1557 {
1558 	struct iovec iov;
1559 
1560 	iov.iov_base = __DECONST(char *, buf);
1561 	iov.iov_len = len;
1562 	return (fetch_writev(conn, &iov, 1));
1563 }
1564 
1565 /*
1566  * Write a vector to a connection w/ timeout
1567  * Note: can modify the iovec.
1568  */
1569 ssize_t
1570 fetch_writev(conn_t *conn, struct iovec *iov, int iovcnt)
1571 {
1572 	struct timeval now, timeout, delta;
1573 	struct pollfd pfd;
1574 	ssize_t wlen, total;
1575 	int deltams;
1576 
1577 	if (fetchTimeout > 0) {
1578 		gettimeofday(&timeout, NULL);
1579 		timeout.tv_sec += fetchTimeout;
1580 	}
1581 
1582 	deltams = INFTIM;
1583 	pfd.fd = conn->sd;
1584 	pfd.events = POLLOUT;
1585 
1586 	total = 0;
1587 	for (;;) {
1588 		/*
1589 		 * The socket is non-blocking.  Instead of the canonical
1590 		 * poll() -> write(), we do the following:
1591 		 *
1592 		 * 1) call write() or SSL_write().
1593 		 * 2) if we wrote everything, return success.
1594 		 * 3) if write() or SSL_write() signaled EOF before we
1595 		 *    wrote everything, return -1.
1596 		 * 4) if an error occurred, return -1.
1597 		 * 5) if we did not write everything but we're not at EOF,
1598 		 *    call poll().
1599 		 */
1600 #ifdef WITH_SSL
1601 		if (conn->ssl != NULL) {
1602 			wlen = fetch_ssl_write(conn->ssl,
1603 			    iov->iov_base, iov->iov_len);
1604 		} else
1605 #endif
1606 			wlen = writev(conn->sd, iov, iovcnt);
1607 		if (wlen > 0) {
1608 			/* something was written */
1609 			total += wlen;
1610 			/* skip iovs which were completely written */
1611 			while (iovcnt > 0 && wlen >= (ssize_t)iov->iov_len) {
1612 				wlen -= iov->iov_len;
1613 				iov++;
1614 				iovcnt--;
1615 			}
1616 			/* are we done? */
1617 			if (iovcnt == 0)
1618 				break;
1619 			/* skip written portion of current iov */
1620 			iov->iov_len -= wlen;
1621 			iov->iov_base = __DECONST(char *, iov->iov_base) + wlen;
1622 			/* a partial write is incomplete */
1623 			continue;
1624 		} else if (wlen == 0) {
1625 			/* connection closed */
1626 			break;
1627 		} else if (errno != EAGAIN) {
1628 			/* error */
1629 			if (errno == EINTR && fetchRestartCalls)
1630 				continue;
1631 			fetch_syserr();
1632 			break;
1633 		}
1634 		/* check what's left of our timeout */
1635 		if (fetchTimeout > 0) {
1636 			gettimeofday(&now, NULL);
1637 			if (!timercmp(&timeout, &now, >)) {
1638 				errno = ETIMEDOUT;
1639 				fetch_syserr();
1640 				return (-1);
1641 			}
1642 			timersub(&timeout, &now, &delta);
1643 			deltams = delta.tv_sec * 1000 +
1644 			    delta.tv_usec / 1000;
1645 		}
1646 		/* wait for the socket to become writeable */
1647 		if (poll(&pfd, 1, deltams) < 0) {
1648 			if (errno == EAGAIN)
1649 				continue;
1650 			if (errno == EINTR && fetchRestartCalls)
1651 				continue;
1652 			return (-1);
1653 		}
1654 	}
1655 	/* a partial write is failure */
1656 	if (iovcnt > 0)
1657 		return (-1);
1658 	return (total);
1659 }
1660 
1661 
1662 /*
1663  * Write a line of text to a connection w/ timeout
1664  */
1665 int
1666 fetch_putln(conn_t *conn, const char *str, size_t len)
1667 {
1668 	struct iovec iov[2];
1669 	int ret;
1670 
1671 	DEBUGF(">>> %s\n", str);
1672 	iov[0].iov_base = __DECONST(char *, str);
1673 	iov[0].iov_len = len;
1674 	iov[1].iov_base = __DECONST(char *, ENDL);
1675 	iov[1].iov_len = sizeof(ENDL);
1676 	if (len == 0)
1677 		ret = fetch_writev(conn, &iov[1], 1);
1678 	else
1679 		ret = fetch_writev(conn, iov, 2);
1680 	if (ret == -1)
1681 		return (-1);
1682 	return (0);
1683 }
1684 
1685 
1686 /*
1687  * Close connection
1688  */
1689 int
1690 fetch_close(conn_t *conn)
1691 {
1692 	int ret;
1693 
1694 	if (--conn->ref > 0)
1695 		return (0);
1696 #ifdef WITH_SSL
1697 	if (conn->ssl) {
1698 		SSL_shutdown(conn->ssl);
1699 		SSL_set_connect_state(conn->ssl);
1700 		SSL_free(conn->ssl);
1701 		conn->ssl = NULL;
1702 	}
1703 	if (conn->ssl_ctx) {
1704 		SSL_CTX_free(conn->ssl_ctx);
1705 		conn->ssl_ctx = NULL;
1706 	}
1707 	if (conn->ssl_cert) {
1708 		X509_free(conn->ssl_cert);
1709 		conn->ssl_cert = NULL;
1710 	}
1711 #endif
1712 	ret = close(conn->sd);
1713 	free(conn->buf);
1714 	free(conn);
1715 	return (ret);
1716 }
1717 
1718 
1719 /*** Directory-related utility functions *************************************/
1720 
1721 int
1722 fetch_add_entry(struct url_ent **p, int *size, int *len,
1723     const char *name, struct url_stat *us)
1724 {
1725 	struct url_ent *tmp;
1726 
1727 	if (*p == NULL) {
1728 		*size = 0;
1729 		*len = 0;
1730 	}
1731 
1732 	if (*len >= *size - 1) {
1733 		tmp = reallocarray(*p, *size * 2 + 1, sizeof(**p));
1734 		if (tmp == NULL) {
1735 			errno = ENOMEM;
1736 			fetch_syserr();
1737 			return (-1);
1738 		}
1739 		*size = (*size * 2 + 1);
1740 		*p = tmp;
1741 	}
1742 
1743 	tmp = *p + *len;
1744 	snprintf(tmp->name, PATH_MAX, "%s", name);
1745 	memcpy(&tmp->stat, us, sizeof(*us));
1746 
1747 	(*len)++;
1748 	(++tmp)->name[0] = 0;
1749 
1750 	return (0);
1751 }
1752 
1753 
1754 /*** Authentication-related utility functions ********************************/
1755 
1756 static const char *
1757 fetch_read_word(FILE *f)
1758 {
1759 	static char word[1024];
1760 
1761 	if (fscanf(f, " %1023s ", word) != 1)
1762 		return (NULL);
1763 	return (word);
1764 }
1765 
1766 static int
1767 fetch_netrc_open(void)
1768 {
1769 	struct passwd *pwd;
1770 	char fn[PATH_MAX];
1771 	const char *p;
1772 	int fd, serrno;
1773 
1774 	if ((p = getenv("NETRC")) != NULL) {
1775 		DEBUGF("NETRC=%s\n", p);
1776 		if (snprintf(fn, sizeof(fn), "%s", p) >= (int)sizeof(fn)) {
1777 			fetch_info("$NETRC specifies a file name "
1778 			    "longer than PATH_MAX");
1779 			return (-1);
1780 		}
1781 	} else {
1782 		if ((p = getenv("HOME")) == NULL) {
1783 			if ((pwd = getpwuid(getuid())) == NULL ||
1784 			    (p = pwd->pw_dir) == NULL)
1785 				return (-1);
1786 		}
1787 		if (snprintf(fn, sizeof(fn), "%s/.netrc", p) >= (int)sizeof(fn))
1788 			return (-1);
1789 	}
1790 
1791 	if ((fd = open(fn, O_RDONLY)) < 0) {
1792 		serrno = errno;
1793 		DEBUGF("%s: %s\n", fn, strerror(serrno));
1794 		errno = serrno;
1795 	}
1796 	return (fd);
1797 }
1798 
1799 /*
1800  * Get authentication data for a URL from .netrc
1801  */
1802 int
1803 fetch_netrc_auth(struct url *url)
1804 {
1805 	const char *word;
1806 	int serrno;
1807 	FILE *f;
1808 
1809 	if (url->netrcfd < 0)
1810 		url->netrcfd = fetch_netrc_open();
1811 	if (url->netrcfd < 0)
1812 		return (-1);
1813 	if ((f = fdopen(url->netrcfd, "r")) == NULL) {
1814 		serrno = errno;
1815 		DEBUGF("fdopen(netrcfd): %s", strerror(errno));
1816 		close(url->netrcfd);
1817 		url->netrcfd = -1;
1818 		errno = serrno;
1819 		return (-1);
1820 	}
1821 	rewind(f);
1822 	DEBUGF("searching netrc for %s\n", url->host);
1823 	while ((word = fetch_read_word(f)) != NULL) {
1824 		if (strcmp(word, "default") == 0) {
1825 			DEBUGF("using default netrc settings\n");
1826 			break;
1827 		}
1828 		if (strcmp(word, "machine") == 0 &&
1829 		    (word = fetch_read_word(f)) != NULL &&
1830 		    strcasecmp(word, url->host) == 0) {
1831 			DEBUGF("using netrc settings for %s\n", word);
1832 			break;
1833 		}
1834 	}
1835 	if (word == NULL)
1836 		goto ferr;
1837 	while ((word = fetch_read_word(f)) != NULL) {
1838 		if (strcmp(word, "login") == 0) {
1839 			if ((word = fetch_read_word(f)) == NULL)
1840 				goto ferr;
1841 			if (snprintf(url->user, sizeof(url->user),
1842 				"%s", word) > (int)sizeof(url->user)) {
1843 				fetch_info("login name in .netrc is too long");
1844 				url->user[0] = '\0';
1845 			}
1846 		} else if (strcmp(word, "password") == 0) {
1847 			if ((word = fetch_read_word(f)) == NULL)
1848 				goto ferr;
1849 			if (snprintf(url->pwd, sizeof(url->pwd),
1850 				"%s", word) > (int)sizeof(url->pwd)) {
1851 				fetch_info("password in .netrc is too long");
1852 				url->pwd[0] = '\0';
1853 			}
1854 		} else if (strcmp(word, "account") == 0) {
1855 			if ((word = fetch_read_word(f)) == NULL)
1856 				goto ferr;
1857 			/* XXX not supported! */
1858 		} else {
1859 			break;
1860 		}
1861 	}
1862 	fclose(f);
1863 	url->netrcfd = -1;
1864 	return (0);
1865 ferr:
1866 	serrno = errno;
1867 	fclose(f);
1868 	url->netrcfd = -1;
1869 	errno = serrno;
1870 	return (-1);
1871 }
1872 
1873 /*
1874  * The no_proxy environment variable specifies a set of domains for
1875  * which the proxy should not be consulted; the contents is a comma-,
1876  * or space-separated list of domain names.  A single asterisk will
1877  * override all proxy variables and no transactions will be proxied
1878  * (for compatibility with lynx and curl, see the discussion at
1879  * <http://curl.haxx.se/mail/archive_pre_oct_99/0009.html>).
1880  */
1881 int
1882 fetch_no_proxy_match(const char *host)
1883 {
1884 	const char *no_proxy, *p, *q;
1885 	size_t h_len, d_len;
1886 
1887 	if ((no_proxy = getenv("NO_PROXY")) == NULL &&
1888 	    (no_proxy = getenv("no_proxy")) == NULL)
1889 		return (0);
1890 
1891 	/* asterisk matches any hostname */
1892 	if (strcmp(no_proxy, "*") == 0)
1893 		return (1);
1894 
1895 	h_len = strlen(host);
1896 	p = no_proxy;
1897 	do {
1898 		/* position p at the beginning of a domain suffix */
1899 		while (*p == ',' || isspace((unsigned char)*p))
1900 			p++;
1901 
1902 		/* position q at the first separator character */
1903 		for (q = p; *q; ++q)
1904 			if (*q == ',' || isspace((unsigned char)*q))
1905 				break;
1906 
1907 		d_len = q - p;
1908 		if (d_len > 0 && h_len >= d_len &&
1909 		    strncasecmp(host + h_len - d_len,
1910 			p, d_len) == 0) {
1911 			/* domain name matches */
1912 			return (1);
1913 		}
1914 
1915 		p = q + 1;
1916 	} while (*q);
1917 
1918 	return (0);
1919 }
1920